One method of manufacturing continuously cast copper product uses a wheel and belt type casting machine. The casting machine, or caster, comprises a rotating means for rotating a casting wheel assembly, the casting wheel assembly, and a continuous belt that rides on the surface of the wheel assembly.
The wheel assembly of a wheel and belt type caster comprises a mounting plate for mounting the assembly to the rotating means, a casting ring which has a groove machined into its periphery into which the molten metal is poured and solidified, and a side plate which is fastened to the mounting plate and casting ring to form the wheel assembly. The side plate and the mounting plate are typically fabricated from steel. The copper ring or casting insert is typically manufactured from copper or a copper base alloy. This copper or copper base alloy is soft and is susceptible to damage if force is applied to its periphery or to either of its two sides.
Typical industrial practice for removing the casting wheel assembly from the casting machine utilizes an overhead crane. A hook assembly is attached to the upper portion of the casting wheel assembly and the wheel assembly is removed from the casting machine. The vertically oriented wheel is then moved to a shop area where it is typically placed on the floor or some other work surface for maintenance or repair. However, most maintenance and repair procedures require that the wheel be positioned horizontally.
A typical one hundred twenty (120) inch casting wheel assembly weighs approximately 5400 pounds. Since the surface or periphery of the casting ring extends beyond the surface of the mounting plate and the side plate, the casting ring surface is exposed to the loads and forces directed toward or received by the surface of the casting wheel assembly. Even with careful crane operation, the copper ring can be damaged when the weight load of the assembly is concentrated on the small contact area between the soft copper ring and the floor or horizontal work surface on which it rests. When the wheel rests vertically on the floor horizontal surface, its entire 5400 pound weight load is concentrated on a very small area of the ring's periphery. This load is sufficient to warp the ring. The sides of the casting chamber can be deflected inwardly or outwardly or a flat spot can form on the outer surface of the casting ring. This damage will result in a poor seal between the band member and the copper ring. This poor seal allows molten metal to leak and leads to premature mould failure.
As the casting ring assembly is tilted over onto its side, up to half of its 5400 pound weight will rest on the corner of the casting ring that contacts the horizontal surface. This creates tremendous inward pressure on the mould ring which deflects the ring wall and results in damage to the casting chamber. The same type damage results when the casting ring is returned to an upright position from the horizontal position. The stresses on the mould are the same.
Careful attention on the part of the crane operator can minimize the damage to the soft copper casting rings; however, no degree of care can prevent damage to the ring. There is simply too much weight or load concentrated on too small an area.